China wants a clear explanation from Washington over a report that the U.S. National Security Agency infiltrated servers at the headquarters of telecoms giant Huawei Technologies Co., a Chinese foreign ministry spokesman said on Monday. Hong Lei, the spokesman, said China was “extremely concerned” about the spying allegations. “Recently, the international media has put out a lot of reports about the eavesdropping, surveillance and stealing of secrets by the United States of other countries, including China,” he told a regular briefing. “China has already lodged many complaints with the United States about this.